Genetic dissection and breeding for grain appearance quality in rice

Abstract

Grain quality largely determines the market price of rice. Many consumers pay particular attention to high grain quality, although preferences in terms of grain size, grain shape, storage components, and fragrance are diverse. Grain chalkiness is one of the most important traits in grain appearance in both indica and japonica cultivars. Grain chalkiness critically decreases market value because of grain breakage during milling and decreased cooking and eating qualities. Recent progress in the genetic analysis of grain chalkiness has identified many quantitative trait loci (QTLs) and their underlying genes. These results provide insights into the genetic control of grain quality. To reduce grain chalkiness, breeding programs have introduced several QTLs or genes with large genetic effects into the genetic backgrounds of indica and japonica cultivars. The resultant near-isogenic lines showing high grain quality are good candidates for novel cultivars with improved grain quality.